Bench stripper



JuneZ, 1964 Filed May 5, 1960 T. E. TRETHEWEY ETAL 3,135,145

BENCH STRIPPER 4 Sheets-Sheet 1 410K l farza 1 1964 T. E. TRETHEWEY ETAL 3,135,145

BENCH STRIPPER Filed May 5, 1960 4 Sheets-Sheet 2 IN V EN TORS E agfr fffi/fg pzrfir far/gr 14/ far/rays.

June 1964' T. E. TRETHEWEY ETAL 3,135,145

BENCH STRIPPER Filed May 5, 1960 r 4 Sheets-Sheet I5 J 1964 T. E. TRETHEWEY ETAL 3,135,145

BENCH STRIPPER Filed May 5, 1960 4 Sheets-Sheet 4 United States Patent 3,135,145 BENCH STRIPPER Thomas E. Trethevvey, Sycamore, and Clyde M.

Vipond, .lr., Waterman, Ill., assignors to Ideal Industries, Inc., Sycamore, Ill., a corporation of Delaware Filed May 5, 1960, Ser. No. 27,003

6 Claims. (Cl. 81-9.51)

This invention relates to automatic wire strippers.

One purpose of this invention is to provide an automatic wire stripper operated by fluid or air pressure.

Another purpose is a wire stripper utilizing two rotating blades which are held away from the cutting position by centrifugal force.

Another purpose is a Wire stripper of the type described including improved means for regulating the depth of cut made by the cutting blades.

Another purpose is a Wire stripper utilizing air pressure to operate the cutting blades and including means for regulating or controlling the speed at which the blades move to a cutting or closed position.

Another purpose is a wire stripper of the type described having improved means for varying the length of strip.

Another purpose is an air pressure operated rotary wire stripper effective to strip stranded wire, regardless of the direction in which the strands are wound.

Another purpose is an improved rotary wire stripper of the type described which reduces wear on the bearings.

Another purpose is a rotary wire stripper of the type described in which the thrust used to close the blades is coaxial with the axis of the motor and the axis of rotation of the blades.

Another purpose is a rotary wire stripper of the type described having improved means for accurately controlling the cutting blades for proper stripping of the Wire.

Other purposes will appear in the ensuing specification, drawings and claims.

The invention is illustrated diagrammatically in the following drawings wherein:

FIGURE 1 is a perspective of the bench stripper of our invention showing the stripper enclosed in a suitable housing,

FIGURE 2 is a top plan view of one form of bench stripper with the housing removed,

FIGURE 3 is a section along plane 33 of FIGURE 2,

FIGURE 4 is a section, similar to FIGURE 3, showing a further form of bench stripper,

FIGURE 5 is a side elevation of a further form of bench stripper,

FIGURE 6 is an enlarged section showing the stripper head,

FIGURE 7 is a side view of the stripper head of FIG- URE 6, and

FIGURE 8 is a top View, in part section, showing the piston construction of the strippers of FIGURES 4 and 5 in detail. I

In FIGURE 1, a case or housing or cabinet 10, which may be plastic, metal or otherwise, has a front wall 12 which mounts a conventional on-oif switch 14, an air pressure control knob 16 and a plug 18 for use with a foot pedal attachment. The housing may have an opening 20 along one edge to expose the control knobs, as will be more fully explained hereinafter. One corner of the housing 10 may have a door 22 which opens to expose the stripper head for cleaning, servicing or otherwise. The front wall 12 and door 22 each have a semicircular opening, 24 and 26 respectively, which, when the door is closed, define the opening for inserting the wire into the stripper head.

FIGURES 2 and 3 show the stripper head with the housing 10 removed. A base 28 mounts aframe 30 having a central portion 32 spaced from the base 28 and supporting a bearing housing 34. Within the hearing housing 34 are bearings 36 and 38 which support a rotatable outer sleeve 40. A sheave 42 is keyed to the sleeve 40, as at 44, and has a V-groove 46 which receives a belt 48. The belt is driven by an electric motor 50, which as shown in the form of FIGURES 2 and 3 and the form of FIGURE 4, has an axis of rotation which is spaced from and parallel to the axis of rotation of the sleeve 40.

A cylinder 52 may be press fitted or otherwise secured on the sleeve 40 adjacent the sheave 42. A small collar 54 is mounted on the cylinder 52 for rotation therewith. A yoke 56 may be secured at its opposite ends to the collar 54 by screws or the like 58 and, as shown in FIGURE 3, has an inturned portion which fits into the hollow central portion of the cylinder 52. The yoke 56 may have a central aperture or opening 60 so that a rod or shaft 62 may pass therethrough.

Mounted within the hollow sleeve 40 is a second hollow sleeve 64 which may rotate with sleeve 40 and has an end surface, at the left hand end, which is adapted to contact yoke 56. Movement of the inner sleeve 64 toward the left, as shown in FIGURE 3, moves the yoke and the collar 54 to the left. The rod or shaft 62 within sleeve 64 may also rotate during operation.

FIGURE 6 shows the details of the stripper head. Two pins or rods 66 are securely mounted in collar 54 for movement therewith. The forward end of the pins 66 are set in holes or apertures 68 in an outwardly projecting portion 70 of the forward end of the cylinder 52. Each of the pins 66 have a slanted or cam surface 72 which mates With a similarly slanted or cam surface 74 forming the outer edge of the stripper blades 76. The stripper blades 76 reciprocate or move radially in radial slots 78 formed in the end of the cylinder 52. The inner edge or inner surface of each of the stripper blades 76 has a cutting edge 80, and when the blades come together, the rotation thereof will cut the insulation or covering on the wire positioned in the stripper head. An aligning block 82 having a central tapered opening 84 which opens into a small bore 86 may be threadedly engaged, as at 88, with the forward end of cylinder 52. The aligning block 82 properly positions the wire between the cutter blades.

The stripper blades 76 are freely slideable in theslots 78 so that during operation, as the stripper head rotates the centrifugal force forces the stripper blades outward, such as shown in FIGURE 6. In addition, we have placed a coiled spring 90 around each of the pins 66. The springs 90 are seated against the cylindrical portion 70 and bias the collar 54 and the pins 66 away from the stripper blades 76. The springs 90 cooperate 'with the centrifugal force developed to keep the blades 76 in an out position. In order to strip the insulation off a wire which has been placed between the rotating blades 76, the collar 54 is moved to the left, as shown in FIGURE 6, by a mechanism hereinafter described. Movement of collar 54 and hence pins 66 to the left drives the stripper blades 76 radially inward or towards the wire positioned in aligning block 82.

As it is important that only the proper length of wire be stripped, an adjustable wire stop 92 may be positioned on rod 62 in alignment with openings 84 and 86. The wire stop may be adjusted by a mechanism hereinafter described.

Turning to FIGURES 2 and 3, the sleeve 64 has a bearing 94 mounted at the right end thereof. As shown in FIGURE 3, the stripper is in the unoperated position and hence the bearing 94 is spaced from a knurl or wheel 96 which is adjustably mounted in an interiorly threaded block 98 positioned on the base 32. The knurl is radially spaced from sleeve 64 and serves as a stop for the bearing when it is moved towards the left, as shown in FIGURE 3, or to the operated position. In other words, the particular position of the knurl 96 determines the extent of movement of sleeve 64 and hence the depth of cut made by the stripper blades 76. The amount of movement of sleeve 64 determines the extent of movement of pins 66, and accordingly, as the pins determine the distance the ripper blades move inward, the position of the knurl or wheel 96 determines the depth of the cut made by the stripper blades.

Positioned to bear against the far right surface of bearing 94 is a cylindrical actuating block 106 which is reciprocated or moved by a piston rod 102 mounted in a cylinder 104. The cylinder 104 may be suitably mounted on the side of the stripper framework and includes an apertured cover plate 106 threadedly secured to the cylinder 104 and having a cylindrical extension 108 which mounts a spring 110,. The spring 110 biases piston head 112 and hence the piston 102 toward the right or away from the bearing 94.

The cylinder 104 has an air port 114 to admit air pressure or some other suitable fluid pressure behind the piston to move the piston toward the bearing 94. A suitable hose 116 connects port 114 to a solenoid 118 and an air pressure inlet 120, on the opposite side of the solenoid. The air line 120 connects into a needle valve indicated at 122 which is controlled by air pressure knob 16. Knob 16 controls the needle valve and hence the amount of air pressure which may flow through the solenoid 118, when operated, to line 116 and to cylinder 1M. As the amount of air pressure or fluid pressure admitted into the cylinder determines the speed at which the piston moves and so the speed at which sleeve 64 moves to the left, or to the cutting position, the knob 16 determines the speed at which the cutter blades come together at the cutting position. Thus, the knob 16 is a further means of controlling the cutter blades for precise stripping. In operation, the solenoid valve may be operated by a suitable foot pedal connected to plug 18 such that upon pressing the foot pedal, air under pressure passes through the solenoid and to the cylinder 104.

In order to adjust the length of strip or to position the wire stop 92 we have positioned a knurl or wheel 124 on a frame portion 126. The knurl is interiorly threaded and receives a threaded rod or screw 128 which provides a stop for the rod or shaft 62. A small coiled spring 130 biases the rod 62 toward or against the stop or screw 128. By rotating the knurl or wheel 124 the position of the screw 128 is varied to adjust the position of wire stop 92.

In the form of FIGURE 4, the stripper head is the same as shown in FIGURES 2 and 3, and will not be described in detail. Instead of having a sleeve, suchtas the sleeve 64, to move the yoke, pins and cutter blades, the form of FIGURE 4 includes a rod or shaft 132 slidably mounted in a sleeve 134. The rod 132 is adapted to contact the yoke in the same manner as sleeve 64. The sleeve 134 is positioned in bearings 136 and is driven by asheave 138 and belt 140.

The details of the mechanism for reciprocating or driving rod 132 are shown in FIGURE 8. A piston 142 having a pistonhead 144 is mounted in a cylinder 146 having an air inlet port 148, The port 148 may be connected to a solenoid, needle valve and source of pressure such as described before. The piston 142 extends outwardly and into a small sleeve 150 which has an enlarged open end 152 which receives the right hand end, as shown in FIGURE 4, of shaft 132 and positions the shaft against the piston 142.

The cylinder 146 includes a cover 154 mounted on an interiorly threaded cylinder 156. A second cylinder 158, threaded on the outside, is received within cylinder 156 and has an inner bore 160 forming a seat 162 for a spring 164, coiled around thepiston 142. The spring 164 normally biases the piston 142 to the unoperated position.

A cover 166 is mounted on cylinder 156 and provides a stop for knurl or Wheel 16 8. The exterior of cylinder 158 is threaded so that wheel 168 may be rotated thereon.

A second knurl or wheel 178 is fixed on cylinder 158 and provides a means for rotating the cylinder. In other words, wheel 168 is a locking wheel or ring and wheel 173 is an adjusting ring. The combination of the two wheels provide a means for adjusting the length or distance of movement of shaft 132 and hence the depth to which the blades will cut. This adjustment is similar to that provided by wheel 96 in the form of FIGURES 2 and 3.

The locking wheel 168 is rotated on cylinder 158 to loosen the cylinder and then wheel 178 is turned to properly set the assembly to stop the piston after the proper length of travel depending upon the particular depth of cut required.

It should be noted that the form of the invention in FIGURE 4 is somewhat similar to the form shown in FIGURES 2 and 3 in that the axis of thrust and the axis of rotation of the cutter blades is parallel to and spaced from the axis of rotation of the drive motor 50. In the form shown in FIGURE 5 the axis of thrust and the axis of rotation of the drive motor and the cutter blades are the same. Drive motor 180 has a hollow drive shaft to receive a rod 182 which is reciprocated or moved by a drive mechanism indicated generally at 184 and identical to that shown in FIGURES 4 and 8. The details of the stripper head for the form in FIGURE 5 have also not been shown as they are similar to the forms as shown before. Reciprocation or movement of rod 182 is effective to close the cutter blades as was described in the other forms of the invention.

The use, operation and function of the invention are as follows:

Shown and described herein is an improved rotary wire stripper operated by fluid pressure, for example air pressure. The stripper shown has numerous advantages over those previously known and in particular has improved adjusting means. For example, in order to properly determine the length of strip we have provided a wire stop which may be adjusted by a wheel, such as the wheel 124.

Further adjustment resides in air pressure control knob 16 which determines the pressure of the fluid or air admitted to the piston and cylinder that drives the blades to the cutting position. By regulating the amount of pressure it is possible to regulate the speed at which the knives or blades close. This regulation is particularly desirable when it is not possible to provide an air pressure system with proper regulation. For example, if the air pressure available is too high for proper operation the extreme force produced by such a pressure if uncontrolled might force the blades together at such a rapid rate that they would cut or nick the wire. In other words, the blades would lose contact with the cam surfaces or pins 66 as they drove toward the wire because of the extreme speed at which they moved. Since in many forms of electrical work even a small nick on the wire ruins the wire, it is necessary to adequately and properly control the speed at which the blades close so that the wire is not damaged. 7

A further adjustment necessary in a wire stripper of the type described is one that determines the proper depth of the cut. As wires of many different sizes may be stripped in the wire stripper shown, there must be an easy and simple adjustment for properly setting the cutting blades. In the form shown in FIGURES 2 and 3, we use a wheel 96 which adjusts the length of travel or distance through which sleeve 64 moves, hence controlling the depth of the cutting blades. In the form of FIG- URES 4 and 5, We use two wheels one of which is a looking wheel and the other controlling the distance through which the piston 142moves. The piston controls the depth of cut made by the rotating cutting blades. In every case, all adjustment may be made during operation.

In all forms of the invention the knurls or wheels have been made large to provide micrometer adjustment for both the depth of cut and length of wire stripped.

To briefly describe the operation of the form shown in FIGURES 2 and 3, when air pressure is admitted into cylinder 104, piston 102 drives to the left moving bearing 94 and sleeve 64 to the left. As the sleeve moves to the left it moves the yoke 56 and hence moves the pins 66 against the cutting blades. The mating cam surfaces of the pins and cutting blades cooperate to drive the cutting blades radially inward or towards the wire to be stripped. Centrifugal force in cooperation with springs 90 keep the blades in the out position when the stripper is not being used. The blades may be kept far enough apart so that thereis no possibility of a wire being cut or nicked as it is being pushed into the stripper head.

In the form shown in FIGURES 4 and 5 movement of piston 142 under the influence of air pressure admitted through port 148 drives either shaft 132 or shaft 182 towards the left and hence moves the yoke, pins and cutting blades as described before.

In order to control the solenoid valve 118 which controls the flow of air pressure to the piston and cylinder moving the cutter blade, we may use a foot pedal or the like connected to the unit through plug 18. Such a foot pedal will leave both hands of the operator free to strip the wires.

It should be noted that the drive motors shown in the various forms of the invention can rotate in either direction, hence making it possible to strip stranded wire regardless of the direction it is wound.

Of particular advantage in the form shown in FIG- URES 4 and 5 is the fact that there is no side strain placed on the bearings supporting the thrust mechanism as the piston is in alignment with the thrust mechanism. Note that in the form shown in FIGURES 2 and 3 the piston is offset from the thrust mechanism hence putting some strain on the bearing 94. However, in the form shown in FIGURES 4 and 5, the bearings are in alignment with the piston hence removing much of the strain on the bearings. In addition, in the form shown in FIGURE 5 the axis of rotation of the motor is the same as the thrust axis. This removes any additional side strain put on the bearings by the belt and sheave shown in FIGURES 2, 3 and 4. The form shown in FIGURE 5 is very compact and provides an excellent wire stripper.

Whereas the preferred form of the invention has been shown and described herein it should be realized that 6 there are many modifications, substitutions and alterations thereto within the scope of the following claims.

We claim:

1. A wire stripper including a pair of rotating stripper blades movable toward each other to a cutting position and away from each other to a non-cutting position, a pair of movable pins, one in contact with each of said cutting blades and effective to move said blades to a cutting position upon movement in one direction, a spring encircling each pin and urging it away from the blades, means for moving said pins toward said blades including a hollow elongated sleeve, means for reciprocating said sleeve including a piston, means for reciprocating said piston, means for rotating said pins and cutting blades, means for adjusting the length of movement of said sleeve to regulate the depth of cut, and means for varying the length of wire stripped including a movable rod positioned within said sleeve, a manual adjustment member for moving said rod within said sleeve, and yielding means biasing said rod away from said blades.

2. The structure of claim 1 further characterized in that the means for rotating said blades includes a motor, said piston being reciprocal in a path parallel to but spaced from the motor axis, and said blades rotating about an axis parallel to and spaced from said motor axis.

3. The structure of claim 1 further characterized by yielding means biasing said piston away from said sleeve.

4. The structure of claim 1 further characterized by a yoke secured to said pins, said sleeve being in contact with said yoke to reciprocate it.

5. The structure of claim 1 further characterized in that said piston moves in a path radially offset from the path of movement of said sleeve.

6. The structure of claim 1 further characterized by air pressure means for reciprocating said piston, and means for regulating the pressure supplied to said piston to vary the speed at which said blades move to the cutting position.

References Cited in the file of this patent UNITED STATES PATENTS 1,724,635 Bath Aug. 13, 1929 1,782,692 Lawson Nov. 25, 1930 1,904,112 Achard Apr. 18, 1933 2,239,755 Montgomery Apr. 29, 1941 2,765,685 Stratman et a1 Oct. 9, 1956 2,826,871 Baker Mar. 18, 1958 2,915,928 Felts et al. Dec. 8, 1959 2,920,513 Baird et al. Jan. 12, 1960 3,074,301 Carpenter Jan. 22, 1963 

1. A WIRE STRIPPER INCLUDING A PAIR OF ROTATING STRIPPER BLADES MOVABLE TOWARD EACH OTHER TO A CUTTING POSITION AND AWAY FROM EACH OTHER TO A NON-CUTTING POSITION, A PAIR OF MOVABLE PINS, ONE IN CONTACT WITH EACH OF SAID CUTTING BLADES AND EFFECTIVE TO MOVE SAID BLADES TO A CUTTING POSITION UPON MOVEMENT IN ONE DIRECTION, A SPRING ENCIRCLING EACH PIN AND URGING IT AWAY FROM THE BLADES, MEANS FOR MOVING SAID PINS TOWARD SAID BLADES INCLUDING A HOLLOW ELONGATED SLEEVE, MEANS FOR RECIPROCATING SAID SLEEVE INCLUDING A PISTON, MEANS FOR RECIPROCATING SAID PISTON, MEANS FOR ROTATING SAID PINS AND CUTTING BLADES, MEANS FOR ADJUSTING THE LENGTH OF MOVEMENT OF SAID SLEEVE TO REGULATE THE DEPTH OF CUT, AND MEANS FOR VARYING THE LENGTH OF WIRE STRIPPED INCLUDING A MOVABLE ROD POSITIONED WITHIN SAID SLEEVE, A MANUAL ADJUSTMENT MEMBER FOR MOVING SAID ROD WITHIN SAID SLEEVE, AND YIELDING MEANS BIASING SAID ROD AWAY FROM SAID BLADES. 